Xanthophyll β-Cryptoxanthin Inhibits Highly Refined Carbohydrate Diet-Promoted Hepatocellular Carcinoma Progression in Mice

Opuntia ficus-indica (L.) Mill. - anticancer properties and phytochemicals: current trends and future perspectives

Cancer is a leading cause of mortality worldwide, and conventional cancer therapies such as chemotherapy and radiotherapy often result in undesirable and adverse effects. Natural products have emerged as a promising alternative for cancer treatment, with comparatively fewer side effects reported. Opuntia ficus-indica (L.) Mill., a member of the Cactaceae family, contains a diverse array of phytochemicals, including flavonoids, polyphenols, betalains, and tannins, which have been shown to exhibit potent anticancer properties. Various parts of the Opuntia plant, including the fruits, stems/cladodes, and roots, have demonstrated cytotoxic effects against malignant cell lines in numerous studies. This review comprehensively summarizes the anticancer attributes of the phytochemicals found in Opuntia ficus-indica (L.) Mill., highlighting their potential as natural cancer prevention and treatment agents. Bibliometric metric analysis of PubMed and Scopus-retrieved data using VOSviewer as well as QDA analysis provide further insights and niche to be explored. Most anticancer studies on Opuntia ficus-indica and its purified metabolites are related to colorectal/colon cancer, followed by melanoma and breast cancer. Very little attention has been paid to leukemia, thyroid, endometrial, liver, and prostate cancer, and it could be considered an opportunity for researchers to explore O. ficus-indica and its metabolites against these cancers. The most notable mechanisms expressed and validated in those studies are apoptosis, cell cycle arrest (G0/G1 and G2/M), Bcl-2 modulation, antiproliferative, oxidative stress-mediated mechanisms, and cytochrome c. We have also observed that cladodes and fruits of O. ficus-indica have been more studied than other plant parts, which again opens the opportunity for the researchers to explore. Further, cell line-based studies dominated, and very few studies were related to animal-based experiments. The Zebrafish model is another platform to explore. However, it seems like more in-depth studies are required to ascertain clinical utility of this biosustainable resource O. ficus-indica.

Streptomyces Bioactive Metabolites Prevent Liver Cancer through Apoptosis, Inhibiting Oxidative Stress and Inflammatory Markers in Diethylnitrosamine-Induced Hepatocellular Carcinoma

A safe and effective treatment for liver cancer is still elusive despite all attempts. Biomolecules produced from natural products and their derivatives are potential sources of new anticancer medications. This study aimed to investigate the anticancer potential of a Streptomyces sp. bacterial extract against diethylnitrosamine (DEN)-induced liver cancer in Swiss albino mice and explore the underlying cellular and molecular mechanisms. The ethyl acetate extract of a Streptomyces sp. was screened for its potential anticancer activities against HepG-2 using the MTT assay, and the IC₅₀ was also determined. Gas chromatography-mass spectrometric analysis was used to identify the chemical constituents of the Streptomyces extract. Mice were administered DEN at the age of 2 weeks, and from week 32 until week 36 (4 weeks), they received two doses of Streptomyces extract (25 and 50 mg/kg body weight) orally daily. The Streptomyces extract contains 29 different compounds, according to the GC-MS analysis. The rate of HepG-2 growth was dramatically reduced by the Streptomyces extract. In the mice model. Streptomyces extract considerably lessened the negative effects of DEN on liver functions at both doses. Alpha-fetoprotein (AFP) levels were significantly (p < 0.001) decreased, and P53 mRNA expression was increased, both of which were signs that Streptomyces extract was suppressing carcinogenesis. This anticancer effect was also supported by histological analysis. Streptomyces extract therapy additionally stopped DEN-induced alterations in hepatic oxidative stress and enhanced antioxidant activity. Additionally, Streptomyces extract reduced DEN-induced inflammation, as shown by the decline in interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) levels. Additionally, the Streptomyces extract administration dramatically boosted Bax and caspase-3 levels while decreasing Bcl-2 expressions in the liver according to the Immunohistochemistry examination. In summary, Streptomyces extract is reported here as a potent chemopreventive agent against hepatocellular carcinoma through multiple mechanisms, including inhibiting oxidative stress, cell apoptosis, and inflammation.

β-Cryptoxanthin Attenuates Cigarette-Smoke-Induced Lung Lesions in the Absence of Carotenoid Cleavage Enzymes (BCO1/BCO2) in Mice

High dietary intake of β-cryptoxanthin (BCX, an oxygenated provitamin A carotenoid) is associated with a lower risk of lung disease in smokers. BCX can be cleaved by β-carotene-15,15'-oxygenase (BCO1) and β-carotene-9',10'-oxygenase (BCO2) to produce retinol and apo-10'-carotenoids. We investigated whether BCX has protective effects against cigarette smoke (CS)-induced lung injury, dependent or independent of BCO1/BCO2 and their metabolites. Both BCO1^-/-/BCO2^-/- double knockout mice (DKO) and wild type (WT) littermates were supplemented with BCX 14 days and then exposed to CS for an additional 14 days. CS exposure significantly induced macrophage and neutrophil infiltration in the lung tissues of mice, regardless of genotypes, compared to the non-exposed littermates. BCX treatment significantly inhibited CS-induced inflammatory cell infiltration, hyperplasia in the bronchial epithelium, and enlarged alveolar airspaces in both WT and DKO mice, regardless of sex. The protective effects of BCX were associated with lower expression of IL-6, TNF-α, and matrix metalloproteinases-2 and -9. BCX treatment led to a significant increase in hepatic BCX levels in DKO mice, but not in WT mice, which had significant increase in hepatic retinol concentration. No apo-10'-carotenoids were detected in any of the groups. In vitro BCX, at comparable doses of 3-OH-β-apo-10'-carotenal, was effective at inhibiting the lipopolysaccharide-induced inflammatory response in a human bronchial epithelial cell line. These data indicate that BCX can serve as an effective protective agent against CS-induced lung lesions in the absence of carotenoid cleavage enzymes.

Hepatocellular Carcinoma Chemoprevention with Generic Agents

Liver cancer, mainly hepatocellular carcinoma (HCC), remains a major cause of cancer-related death worldwide. With the global epidemic of obesity, the major HCC etiologies have been dynamically shifting from viral to metabolic liver diseases. This change has made HCC prevention difficult with increasingly elusive at-risk populations as rational target for preventive interventions. Besides ongoing efforts to reduce obesity and metabolic disorders, chemoprevention in patients who already have metabolic liver diseases may have a significant impact on the poor HCC prognosis. Hepatitis B- and hepatitis C-related HCC incidences have been substantially reduced by the new antivirals, but HCC risk can persist over a decade even after successful viral treatment, highlighting the need for HCC-preventive measures also in these patients. Experimental and retrospective studies have suggested potential utility of generic agents such as lipophilic statins and aspirin for HCC chemoprevention given their well-characterized safety profile, although anticipated efficacy may be modest. In this review, we overview recent clinical and translational studies of generic agents in the context of HCC chemoprevention under the contemporary HCC etiologies. We also discuss newly emerging approaches to overcome the challenges in clinical testing of the agents to facilitate their clinical translation.

Carotenoid fates in plant foods: Chemical changes from farm to table and nutrition

Carotenoids in plant foods are sources of pro-vitamin A and nutrients with several health benefits, including antioxidant and anticancer activities. However, humans cannot synthesize carotenoids de novo and must obtain them from the diet, typically via plant foods. We review the chemical changes of carotenoids in plant foods from farm to table and nutrition, including nutrient release and degradation during processing and metabolism in vivo. We also describe the influencing factors and proposals corresponding to enhancing the release, retention and utilization of carotenoids, thus benefiting human health. Processing methods influence the release and degradation of carotenoids, and nonthermal processing may optimize processing effects. The carotenoid profile, food matrix, and body status influence the digestion, absorption, and biotransformation of carotenoids in vivo; food design (diet and carotenoid delivery systems) can increase the bioavailability levels of carotenoids in the human body. In this review, the dynamic fate of carotenoids in plant foods is summarized systematically and deeply, focusing on changes in their chemical structure; identifying critical control points and influencing factors to facilitate carotenoid regulation; and suggesting multi-dimensional strategies based on the current state of food processing industries to achieve health benefits for consumers.

Roles and regulation of histone acetylation in hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is the most frequent malignant tumor of the liver, but its prognosis is poor. Histone acetylation is an important epigenetic regulatory mode that modulates chromatin structure and transcriptional status to control gene expression in eukaryotic cells. Generally, histone acetylation and deacetylation processes are controlled by the opposing activities of histone acetyltransferases (HATs) and histone deacetylases (HDACs). Dysregulation of histone modification is reported to drive aberrant transcriptional programmes that facilitate liver cancer onset and progression. Emerging studies have demonstrated that several HDAC inhibitors exert tumor-suppressive properties via activation of various cell death molecular pathways in HCC. However, the complexity involved in the epigenetic transcription modifications and non-epigenetic cellular signaling processes limit their potential clinical applications. This review brings an in-depth view of the oncogenic mechanisms reported to be related to aberrant HCC-associated histone acetylation, which might provide new insights into the effective therapeutic strategies to prevent and treat HCC.

Association of Retinol and Carotenoids Content in Diet and Serum With Risk for Colorectal Cancer: A Meta-Analysis

Background

Colorectal cancer (CRC) risk is linked to serum and dietary retinol and carotenoids, according to clinical and epidemiological research. However, the findings are not consistent. As a result, we did this meta-analysis to determine the link between them.

Methods

From 2000 through 2022, the PubMed, Web of Science, and Embase databases, as well as pertinent article references, were searched and filtered based on inclusion and exclusion criteria and literature quality ratings. High and low intake were used as controls, and OR (odds ratio) or RR (relative risk) and 95% confidence interval were extracted. The extracted data were plotted and analyzed using Stata12.0 software.

Results

A total of 22 relevant studies were included, including 18 studies related to diet and 4 studies related to serum. For high and low intake or concentration controls, the pooled OR was as follows: β-carotene (OR = 0.89, 95% CI: 0.78–1.03), α-carotene (OR = 0.87, 95% CI: 0.72–1.03), lycopene (OR = 0.93, 95% CI: 0.81–1.07), lutein/zeaxanthin (OR = 0.96, 95% CI: 0.87–1.07), β-cryptoxanthin (OR = 0.70, 95% CI: 0.48–1.01), total carotenoids (OR = 0.97, 95% CI: 0.81–1.15), retinol (OR = 0.99, 95% CI: 0.89–1.10), serum carotenoids (OR = 0.73, 95% CI: 0.58–0.93), serum retinol (OR = 0.62, 95% CI: 0.26–1.49). Subgroup analysis was performed according to tumor type, study type and sex.

Conclusion

Total carotenoid intake and Lutein/Zeaxanthin intake were not associated with CRC risk. High β-carotene, α-carotene, lycopene, and β-cryptoxanthin all tended to reduce CRC risk. Serum carotenoid concentrations were significantly inversely associated with CRC risk.

Molecular alterations that precede the establishment of the hallmarks of cancer: An approach on the prevention of hepatocarcinogenesis

Chronic liver injury promotes the molecular alterations that precede the establishment of cancer. Usually, several decades of chronic insults are needed to develop the most common primary liver tumor known as hepatocellular carcinoma. As other cancer types, liver cancer cells are governed by a common set of rules collectively called the hallmarks of cancer. Although those rules have provided a conceptual framework for understanding the complex pathophysiology of established tumors, therapeutic options are still ineffective in advanced stages. Thus, the molecular alterations that precede the establishment of cancer remain an attractive target for therapeutic interventions. Here, we first summarize the chemopreventive interventions targeting the early liver carcinogenesis stages. After an integrative analysis on the plethora of molecular alterations regulated by anticancer agents, we then underline and discuss that two critical processes namely oxidative stress and genetic alterations, play the role of 'dirty work laborer' in the initial cell damage and drive the transformation of preneoplastic into neoplastic cells, respectively; besides, the activation of cellular senescence works as a key mechanism in attempting to prevent the onset and establishment of liver cancer. Whereas the detrimental effects of the binomial made up of oxidative stress and genetic alterations are either eliminated or reduced, senescence activation is promoted by anticancer agents. We argue that collectively, oxidative stress, genetic alterations, and senescence are key events that influence the fate of initiated cells and the establishment of the hallmarks of cancer.

Anti-Inflammatory and Anticancer Effects of Microalgal Carotenoids

Acute inflammation is a key component of the immune system’s response to pathogens, toxic agents, or tissue injury, involving the stimulation of defense mechanisms aimed to removing pathogenic factors and restoring tissue homeostasis. However, uncontrolled acute inflammatory response may lead to chronic inflammation, which is involved in the development of many diseases, including cancer. Nowadays, the need to find new potential therapeutic compounds has raised the worldwide scientific interest to study the marine environment. Specifically, microalgae are considered rich sources of bioactive molecules, such as carotenoids, which are natural isoprenoid pigments with important beneficial effects for health due to their biological activities. Carotenoids are essential nutrients for mammals, but they are unable to synthesize them; instead, a dietary intake of these compounds is required. Carotenoids are classified as carotenes (hydrocarbon carotenoids), such as α- and β-carotene, and xanthophylls (oxygenate derivatives) including zeaxanthin, astaxanthin, fucoxanthin, lutein, α- and β-cryptoxanthin, and canthaxanthin. This review summarizes the present up-to-date knowledge of the anti-inflammatory and anticancer activities of microalgal carotenoids both in vitro and in vivo, as well as the latest status of human studies for their potential use in prevention and treatment of inflammatory diseases and cancer.

Promotion effects of DEHP on hepatocellular carcinoma models: up-regulation of PD-L1 by activating the JAK2/STAT3 pathway

Di(2-ethylhexyl) phthalate (DEHP), as an endocrine disruptor, is often used as a plasticizer in various polyvinyl chloride plastic products and medical consumables. Epidemiological studies have shown that long-term large intake of DEHP may be a risk factor for liver dysfunction. Long-term exposure to DEHP is associated with liver disease and aggravates the progression of chronic liver injury. However, the effects of DEHP on hepatocellular carcinoma (HCC) are rarely studied. In this study, we sought to determine the effects of DEHP on HCC induced by carbon tetrachloride combined with diethylnitrosamine, and further study its molecular mechanism. It was found that DEHP exposure significantly promotes tumor immune escape and activates signaling pathways involved in related protein expression of tumor immune escape, including PD-L1, JAK2, and STAT3. In addition, the trends observed in the HepG2 cells assay are consistent with vivo conditions. In summary, DEHP may play a tumor-promoting role in HCC mice and IFN-γ stimulated HepG2 cells, which may be related to the JAK2/STAT3 signaling pathway.

Mechanistic understanding of β-cryptoxanthin and lycopene in cancer prevention in animal models

To better understand the potential function of carotenoids in the chemoprevention of cancers, mechanistic understanding of carotenoid action on genetic and epigenetic signaling pathways is critically needed for human studies. The use of appropriate animal models is the most justifiable approach to resolve mechanistic issues regarding protective effects of carotenoids at specific organs and tissue sites. While the initial impetus for studying the benefits of carotenoids in cancer prevention was their antioxidant capacity and pro-vitamin A activity, significant advances have been made in the understanding of the action of carotenoids with regards to other mechanisms. This review will focus on two common carotenoids, provitamin A carotenoid β-cryptoxanthin and non-provitamin A carotenoid lycopene, as promising chemopreventive agents or chemotherapeutic compounds against cancer development and progression. We reviewed animal studies demonstrating that β-cryptoxanthin and lycopene effectively prevent the development or progression of various cancers and the potential mechanisms involved. We highlight recent research that the biological functions of β-cryptoxanthin and lycopene are mediated, partially via their oxidative metabolites, through their effects on key molecular targeting events, such as NF-κB signaling pathway, RAR/PPARs signaling, SIRT1 signaling pathway, and p53 tumor suppressor pathways. The molecular targets by β-cryptoxanthin and lycopene, offer new opportunities to further our understanding of common and distinct mechanisms that involve carotenoids in cancer prevention. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.